Sym-Tetrazine

Di amino-sym-tetrazine (called 3.6-Diamr no-l 2 4.5-tetrazin or 3 6TDiimino-1.2.3 6T tetrahydro-l 2.4.5-tetrazin in Ger),... 

N — n = CH mw 84.08, N 66.64% lt-yel prisms (from eth or benz), mp 125-26°(dec) readily sol in w ale si sol in eth benz can be prepd by reduction of sym-tetrazine with H2S in cold aq soln, or with Zn dust glac acetic acid in ether and from hydrazo-formaldehyde-hydrazone by soln in dil glac acetic acid (Refs 1,2,3 4). Its expl props were not detd... 

Dihydro-sym-tetrazine-3,6-dicarboxylic Acid [called 1.2-Dihydro-1.2.4.5-tetrazindicarbon saure (3.6) BisdiazoessigsSure or "Triazoessigsaure in Ger],... 

Lin et al, JACS 76, 427(1954) CA 49, 3207(1955) [Describes some Methyl ester derivs, the prepn of 1,2-Dihydro-sym-tetrazine-... 

Di (tetrazolyl-5)-dihydro-sym-tetrazine see 3,6-Bis (2H-tetrazolyl-5)-dihydro-l, 2,4,5-tetrazine 2B157... 

Of the three possible tetrazine systems the 1,2,4,5-tetrazines, also called s-tetrazines or sym- tetrazines, are by far the best known class. The parent compound of the 1,2,4,5-tetrazine series has structure (38) and is numbered as indicated. It was prepared for the first time by Hantzsch and Lehmann in 1900 (00CB3668). The two Kekule structures for (38) are degenerate, as was confirmed by X-ray crystallographic analysis. 

The derivatives of sym-tetrazines were first prepd by T. Curtius in 1888 (Ref 2) and were further investigated by A. Hantzsch et al (Ref 3) No evidence has been found in the literature that the asym-tetrazines have ever been prepd (Refs 7 and 8)... 

An expl K tetrazine salt was prepd by Wood and Bergstrom (Ref 6) with the approx formula K2C3N4 mw 158.26 N 35.41% red cryst mp, highly expl when heated. Not sol in ammonia. Prepn is by reacting an unspecified (vie or sym) tetrazine with K amide in liq ammonia at -40° Refs 1) Beil 26, 353, (111) [212]... 

The other expl tetrazines consist of the parent compd, sym-Tetrazine and its derivatives Sym-Tetrazine (or 1,2,4,5-Tetrazine). C2H2N4 mw 82.08 N 68.27% OB to C02 -97.47% dark purple-red prisms with volatile red fumes... 

See in Vol 2, B143-L under 3,6-Bis (fluorenyli-denhydro)-sym-tetrazine. . 1,2-Dihydro-Sym-Tetrazine-3,6-Dicarboxylic Acid. See in Vol 5, D1267-L Di(Tetrazolyl-5) 3,6- Dihydro-Sym-Tetrazine. See in Vol 2, B157-R to B158-L, under 3,6-Bis (2H-tetrazolyl-5)-dihydro-l, 2,4,5-tetra-zine. . 

Dihydropyridazines are obtained from 1,4-dicarbonyl compounds and hydrazine (Section III,B) or from the reaction of sym-tetrazines and simple ethylenic compounds (Section III,H). There are also a few special reactions, such as that between a tetrahydrofuran and phenylhydrazine, or from a 1,4,5,6-tetrahydropyridazine derivative. The 1,4-dihydro structure has been found to be correct, rather than the 1,6-dihydro structure, postulated earlier for some of these reduced pyridazines (Section III,H). 1,4-Dihydropyridazines can be reduced or oxidized easily and acid treatment of l-tosyl-1,4-dihydropyridazine causes rearrangement to 1-tosylaminopyrrole. ... 

Diimino-l,2,3,6-letra hydro]-sym-tetrazine or 3,6-Diamino-sym-tetrazirie,... 

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